id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
6102	IDAS sensitivity yields absurd results	gerrer@…	Karim Adbdelhak	"I run forward sensitivity analysis using IDA (https://openmodelica.org/doc/OpenModelicaUsersGuide/latest/parametersensitivity.html) on the following model:

model basic
parameter Real mu = 2;
parameter Real lambda = -1;
Real y(start=2, fixed=true);
equation
der(y) = mu*y + lambda;
end basic;

Analytic solution of this model is : 
y(t) = (mu + lambda/mu)*exp(mu*t) - lambda/mu.

Analytic sensitivities are thus:
s_lambda(t) = (exp(mu*t) - 1/mu (--> increases with time)
s_mu(t) = (big nonzero thing)*exp(mu*t) + ctt (--> increases with time)

But sensitivity computation yields:
$Sensitivities.lambda.y = [0.0, ..., 0.0] 
$Sensitivities.mu.y = [0.0, ..., 0.0]."	defect	new	blocker	1.19.0	Backend